Extrusion press



Aug. 16, 1960 Filed July 8, 1957 P. BILLEN EXTRUSIQN PRESS 4 Sheets-Sheet l INVENTOTQ Aug. 16, 1960 P. BILLEN 2,949,186

EXTRUSION PRESS Filed July 8, 1957 I 4 Sheets-Sheet 2 Fig. 2

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Unite EXTRUSION PRESS Peter Billen, Leverkusen-Kuppersteg, Germany, assignor to Schloemann Aktiengesellschaft, Dusseldorf, Germany In extrusion presses the die-holder of which is horizontally slidable upon a die-holder carrier secured to the counter-holder or bolster of the press, the adjusting of the die in a vertical direction is effected when the tools are cold. When the die-holder, slidable with its lower edge upon the carrier, becomes hot, its axis is displaced slightly upwards owing to the expansion of its material, sothat inaccuracies occur in the axial adjustment of the die in relation to the container. If the carrier of the slidable die-holder bears in the usual way with its lower edge upon a ledge secured to the counterholder, an additional vertical displacement of the die axis occurs owing to the heating of the carrier.

The object of thisinvention is to obviate these objectionable displacements of the die'axis arising from heating. For this purpose it proposes two theoretically equivalent solutions. The first solution consists in locating the horizontal sliding path of the die-holder upon its carrier, for instance upon the counter-holder itself, approximately in the horizontal plane passing through the axis of the container. Since according to this embodiment the die-holder is supported exclusively in a plane determined by the axis of the container, its expansion owing to heating takes effect equally upwards and downwards. A displacement of its axis in relation to the axis tion has the advantage that it maintains the height of the die axis accurately under all operative conditions. It does however exhibit constructional disadvantages, owing to the path of sliding of the die-holder having to be arranged at the level of the die axis, that is, of the axis of the press.

The second embodiment obviates this disadvantage. It consists in making the ratio of the vertical distance of the sliding path of the dieholder from the die axis to the vertical distance of the sliding path from a horizontal line at the level at which a die-holder carrier is secured to the counter-holder vary approximately inversely as the ratio of the normal rise of temperature of the dieholder during extrusion to the normal rise of temperature of the die-holder carrier dun'ng extrusion. This is construotionally solved advantageously by securing the dieholder carrier to the counter-holder above the counterholder bore with groove and tongue, while the die-holder is slidable upon a die-holder carrier track located below the die-holder bore.

Two constructional examples of the invention are illustrated in the drawing, in which:

Figure 1 shows a plan view of an extrusion press with the die-holder arranged according to what is described above as the second embodiment of the invention;

Figure 2. shows the part of the press that is pertinent to the invention on a larger scale in axial sectional elevation;

Figure 3 shows a section on the line III--III in Figure 2;

States Patent This soluv Figure 4 shows in axial sectional elevation an extruinvention; and

Figure 5 shows a section on the line V-V in Figure 4.

The container 1 of the metal-extrusion press can be moved to and fro in a horizontal direction by means of piston rods 20, the pistons 21 of which are displaceable by pressure liquid in cylinders 22. The cylinders 22 are mounted above and below the main working cylinder 23, in which a press piston 24 is reciprocable by pressure liquid. The piston 24 carries the press ram 25, which, during the forward stroke, can enter the bore 1a of the container 1, for the purpose of extruding through a die 13 any extrusion metal located therein. The cylinder 23 is connected by four anchoring rods 26 with the counterholder or bolster 2 of the press.

This counter-holder has a horizontal dovetail-shaped groove 3, in which the die-holder carrier 5 is secured with a corresponding tongue 4, the groove and tongue being above the axis of the press. This carrier 5 may if desired be additionally secured against lifting away from the counter-holder by screws 6 and by a lower guiding ledge 7. It is important that the lower surface 8 of the tongue 4 should remain bearing upon the lower surface of the groove 3 notwithstanding any thermally conditioned expansions. The screws 6 will therefore be given sufficient clearance in their bores through the carrier 5 to permit this. When expansion is caused by heating, the lower ledge 9 of the die-holder carrier 5 can expand downwards, because it has vertical clearance in relation to the guiding ledge 7, which merely keeps the dieholder carrier 5 in contact with the counter-holder 2.

The die-holder carrier 5 has a path or slide track 10, upon which the die-holder 11 slides. This die-holder can expand upwards when heated, since it has clearance in a vertical direction, particularly at 12.

The die-holder 11 carries a die 13 by means of a' pressure piece 14. It has, as Figure 3 shows, in addition to the bore that accommodates the pressure piece 14 of the die, a second bore, which serves for the ejection of a solidified billet or for the introduction of a second die 15. The die-holder 11 can be moved to and fro by means of a hydraulically actuated piston 16, which slides in a pressure cylinder 17.

When the die has been adjusted in a cold condition, its axis coincides with the axis 18 of the press. Now when the die-holder 11, which slides upon the path 10, becomes heated, the axis of the die is displaced upwards. At the same time, however, a heating of the die-holder carrier 5 also occurs, but its temperature remains lower than that ofthe die holder 11, since the carrier 5 is located farther from the hot extrusion metal and from the container 1 than the die-holder 11. The die-holder carrier 5 therefore expands less per unit of length than the dieholder 11. The tongue 4 of the die-holder carrier 10 does not shift in a vertical direction in the dovetail groove. That part of it which carries the slide track 10, however, expands downwards. The extent to which the level of the slide track 10 is lowered by this expansion is determined by the coefficient of expansion of the material of the die-holder carrier, the degree of its heating, and the longitudinal dimension L1, namely the vertical distance between the inner or upper edge of the under surface 8 of the tongue 4 and the path 10, while the dimension L, namely the height of the die-holder axis above the path 10, is increased by the expansion of the die-holder '11, which is heated to a higher temperature than the carrier 5. The lengths L and L1 are made, when designing the press, inversely proportional to the ratio between the rise of temperature, to be expected from experience, of the die- Patented Aug. 16, 1960 holder 11, and the rise of temperature, to be expected from experience, of the die-holder carrier 5.

The general arrangement of the press to which Figures 4 and 5 relate corresponds substantially to that of Figure 1. The counter-holder 40 of this press is connected, like that of the press of Figlre 1, by anchoring rods 41, to the cylinder, not shown, of the main press piston. Here the counter-holder 40 directly carries the die-holder 42, in which a pressure piece 43, with the die 44, is inserted in the usual way. Against the pressure piece 43 bears the container 45, which is displaceable by means of rods '46 in the same manner as the container 1 of Figure 1. The counter-holder 40 has a slide track 47, which is located exactly at the level of the axis 48 of the press. Upon this slide track is mounted the dieholder 42. It furthermore bears of course in the usual way, with the surfaces '49 and 59, against the counterholder 40. A flange 51, with a collar 52, engages over the die-holder 42, so that the latter, after insertion behind the collar 52, is held in the direction parallel to the axis 48 of the press. The die-holder is provided with a milled groove 43a, in which the collar 52 of the flange 51 engages. By means of a rod 53 the die-holder 42 can be moved in the direction of the arrow 54. Upon thermal expansion of the die-holder 42 and of the pressure piece '43, and also of the die 44, the axis of all these members remains exactly at the level of the press axis 48.

The surface of the die-holder 42 which mates with and slides on the slide track 47 is slightly inclined at 47a and 47b, in order that the die-holder 42 may be able to pass more easily over the bore 40a of the counterholder 40.

What is claimed is:

1. An extrusion press, comprising: a counter-holder formed with a horizontal groove of dovetail-shaped cross section at a level above the extrusion axis of the press, a die-holder carrier, a horizontal tongue of dovetailshaped cross section on the said carrier engaging in the groove of the counter-holder and thus supporting the weight of the carrier without hindering the expansion and contraction of the carrier in a vertical direction, a horizontal slide track on the carrier below the level of the axis of the press, and a die-holder resting on the said slide track, and so mounted as to be free to expand and contract in a vertical direction.

2. An extrusion press as claimed in claim 1, further comprising: a ledge secured to the counter-holder and engaging the bottom edge of the carrier in such a way as to keep the carrier in contact with the counter-holder without hindering the expansion and contraction of the carrier in a vertical direction.

3. An extrusion press as claimed in claim 2, further comprising: a ledge secured to the front of the carrier and engaging the upper edge of the die-holder in such a way as to keep the die-holder in contact with the carrier without hindering the expansion and contraction of the die-holder in a vertical direction.

References Cited in the file of this patent UNITED STATES PATENTS 

